Body Decomposition the form and rate of decay varies The time of physiological death is usually a “best guess” Exact time of death cannot be accurately determined – there are too many variables

Time of death may be determined by…

1. Body Temperature Also known as Algor Mortis After death, the body loses heat at a rate of 1.5 degrees/ hr until it reaches ambient temperature (same as the environment) But… Rate of temperature change may be altered by: - weight / size - clothing - sun exposure - illness - infestation

2. Rigor Mortis Occurs when muscles contract as ATP (adenosine triphosphate) causes the release of calcium into the muscle Begins ~2 hours after death in the face/neck Entire process takes ~8-12 hrs Remains stiff for another 18 hrs After another 12 hours the muscles relax

What’s this ?! How do you know?

3. Mummification When the body dries out in a hot & dry environment (low humidity inhibits bacterial growth & sucks moisture from tissues!) Results in a leathery, dry, preserved corpse

The natural mummification seen here is a result of the body being in a relatively protected nonburial environment where a sufficient flow of fresh air rapidly dried the soft tissues

4. Adipocere Formation The body’s adipose tissue (fat) turns into a white, waxy, soapy substance Most commonly occurs in moist environments and takes about 3-6 months to form Ex. Drowning victim

This poor sailor drowned and was in the sea for some months before his adipocere-laden body was fished out of the briny deep. Note the condition of ear lobes and nose. Surprisingly, most of his corpse was not consumed by sea creatures

5. Gas Accumulation A.k.a. Putrefaction Bacterial decay of the body Gives off stinky gas such as CO2 & sulfur

6. Lividity Also known as Liver Mortis Darkening of the skin due to lack of oxygen in the blood Blood pools due to gravity May help to indicate if the body was moved

7. The Eyes Corneas become cloudy over the first 24 hrs. after death (faster if eyes are open at t.o.d.) Potassium in the eye liquid (vitreous humor) increases within the first 3-4 days after death

Medical Examination

Medical Examiner’s Job Medical Examiner determines manner and type of death. Examples of manner of death are: Homicide Suicide Accidental Undetermined Examples of type of death are: Stroke Asphyxiation

Medical Examiner & Autopsy The medical examiner is also responsible for performing the autopsy on the body.

Step 1 – Place a toe tag on the body and refrigerate it!

Step 2 – Fingerprints are taken, body is weighed, measured and x-rayed Step 3 – Clothes are examined and stored

Step 4 – Fingernails are examined and scraped for suspect DNA Step 5 – External Examination of bruises, needle marks and skin coloring, hair samples are taken

Step 6 – Mouth is swabbed for victim DNA Step 7 – Collect hair samples Step 8 – Wash the body Step 9 - Fluid samples taken (blood, urine, semen)

Step 10 – Body is dissected (Y-cut) and organs are removed, and weighed Step 11 - A sample of every organ is sent to toxicology Step 12 - Organs are returned to body and it is sewn up